error[E0463]: can't find crate for `syn`

[kernel test robot <lkp@intel.com>]

tree:   https://github.com/intel-lab-lkp/linux/commits/Lorenzo-Stoakes-ARM/kbuild-do-not-allocate-modinfo-in-vmlinux/20260914-102200
head:   e4c41ad4c255b1ef4323410ddd136c5beff8ee3f
commit: 799dcd195cfbecb881a8100ad7fb075179b1b030 kbuild: build rust crates in parallel with the rest of the build
date:   9 days ago
config: x86_64-rhel-9.4-rust (https://download.01.org/0day-ci/archive/20260923/202609231457.9ssfBSKL-lkp@intel.com/config)
compiler: clang version 22.1.8 (https://github.com/llvm/llvm-project ca7933e47d3a3451d81e72ac174dcb5aa28b59d1)
rustc: rustc 1.96.0 (ac68faa20 2026-05-25)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260923/202609231457.9ssfBSKL-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202609231457.9ssfBSKL-lkp@intel.com/

All errors (new ones prefixed by >>):

>> error[E0463]: can't find crate for `syn`
   --> rust/macros/concat_idents.rs:8:5
   |
   8 | use syn::{
   |     ^^^ can't find crate
--
>> error[E0463]: can't find crate for `syn`
   --> rust/pin-init/internal/src/lib.rs:13:5
   |
   13 | use syn::parse_macro_input;
   |     ^^^ can't find crate
--
>> error[E0463]: can't find crate for `syn`
   --> rust/zerocopy-derive/derive/from_bytes.rs:4:5
   |
   4 | use syn::{
   |     ^^^ can't find crate

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